Method of preventing infiltration in wells



Patented Mar. 28, 1939 UNITED STATES aisasoe PATENT OFF ICE METHOD OF PREVENTING mFILTRATlON John J. Grebe, dland, Mich assignor'to The Dow Chemical Company, ,lt iidland, Mich, 'a

corporation of h l'ichigan No Drawing. Application June 24, 1937, "SerialNo. 150,132

dclaims.

This invention relates to methods of shutting off water infiltration in oil and gas wells, wherein a solution of a reagent is introduced into the formation to produce a. precipitate by reacting 5 with the water or with the dissolved constituents thereof. It more particularly concerns an improved method of forming a plugging deposit in the formation, effectively reducing its permeability to the passage of water without materially in reducing its permeability to oil.

It is an object of the invention to provide a method of forming a. precipitate in earth or rock formations resistant to water or brine infiltration which more effectively resists displacement l5 than precipitates heretofore'proposed for the purpose. Other objects and advantages will appear as the description proceeds.

These objects I have found may be realized by introducing into the well an aqueous solution 20 comprising a water-soluble soap and a watersoluble aluminate, under a pressure in excess of that in the water-bearing formation, allowing time for the solution to penetrate the formation, and then releasing the pressure. By'this meth- 5 d the flow of water into a well may be substantially prevented without materially hindering the flow of 011, since the solution is inert to oil;

In carrying out'a treatment, according to the inventio a solution is prepared bydissolving a 3o soluble s 1), such as sodium palmitate, sodium stearate, or like soap formed from a"fatty acid a an a k m b se and a s 1ea i a e s 'so'dium OI" potassium elu'minate'. A considerable variation in the concentration of either a the seen or he-aluminate in the solution em;- ys-X 15 all wa leor example- & lfit fi in 0 w fis b .5 5 an l W ne'r cea' al il l s" bee i e oi 'r. he pro orti of the soap u th I the well and forced into the formation by the application of pressure in the usual manner. The. solution is allowed to remain in the formation by holding the injection 'pressure'to permit the reagent to react with the ground water or dissolved 5 salts therein forming a waterdnsoluble precipi} tate or'deposit in the water-bearing pores. After a 'suflicient period of time,'e. g. from -5 to 15 hours, the pressure is released and any excess solution may beremoved bypumping or bailing. 10

The introduction into aformation wet by brine or hard water of a solution of the type described has the advantage of producing a precipitate which is not as readily displaced from the formation as that produced by either a soap'solution or soluble aluminate solution when the pressure is released. It has the further advantage of being selective in its action-because the solution does not form clogging deposits in contact with oil.

Other modes of applying the principle of my invention may be employed instead of those explained, change being made as regardsthe method herein disclosed, provided the step stated by any of the following claims or the equivalent of such stated step be employed.

- I therefore particularly point out and distinctly claim'as my invention: 1 1. In a method of treating water-bearing formations adjacent the bore of an oil or gas well, the step which consists in introducing into the well a treating solution comprising a. water-soluble aluminate "a water-soluble soap.

'2'. In a method of treating water -bearing formw a ia e where o an r g win a e step which consists in introducing into the w a w almon mea les a waterrs l; "te' 'd a water-soluble soap, the

1 "em-e 1 hens in or gas well, the step which consists in introducing into the well an aqueous treating solution comprising approximately 4 per cent of sodium aluminate and approximately 40 per cent by 5 weight of a water-soluble soap.

6. In a method of treating water-bearing formations adjacent the bore of an oil or gas well, the step which consists in introducing into the well under a pressure in excess of that inthe 10 water-bearing formation a treating solution comprising an alkali-metal aluminate and a. watersoluble soap.

'1. In a method of treating water-bearing formations adjacent the bore of an oil or gas well,

the steps which consist .in introducing into the well under a pressure in excess of that in the water-bearing formation a quantity of water and an aqueous solution comprising an alkali-metal aiuminate and a water-soluble soap.

8. In a method of treating water-bearing formations adJacent the bore of an oil or gas well, the steps which consist in introducing into the well under a pressure in excessof that in the water-bearing formation a treating solution comprising an alkali-metal aluminate, a water-soluble soap and then a quantity of oil.

JOHN J. GREBE. 

